Final Yr’s Mannequin of Ronald Acuña Jr. Is Nowhere in Sight

Aaron Choose, Paul Goldschmidt, and José Abreu aren’t the one latest MVPs off to underwhelming begins in 2024. After placing collectively a season for the ages final yr, Ronald Acuña Jr. has scuffled so far, each when it comes to making contact and hitting for energy. His struggles have coincided with these of a few the staff’s different heavy hitters, with the consequence that the staff lately slipped out of first place within the NL East for the primary time in additional than a yr.

Roughly two years faraway from season-ending surgical procedure to restore a torn ACL, Acuña grew to become the primary participant ever to hit at the very least 40 homers and steal at the very least 70 bases in the identical season. He clubbed 41 dingers and swiped a serious league-leading 73 baggage, aided by a few rule adjustments that elevated per-game stolen base charges by 41% league-wide. Taking part in a career-high 159 video games, he hit .337/.416/.596 whereas main the NL in on-base share, steals, wRC+ (170), plate appearances (735), at-bats (643), complete bases (383), hits (217), runs (149), and WAR (9.0). Regardless of a sturdy problem from Mookie Betts, he was a unanimous decide for the NL MVP award.

The place has that electrifying slugger gone? With greater than a month of play below his belt this season, Acuña has hit simply .267/.373/.359 with 14 steals however simply two homers. Due to his 12.4% stroll charge and his excessive on-base share, that slash line continues to be good for a 116 wRC+, however the 54-point drop in wRC+ is steep, even when it’s “solely” the Sixteenth-largest within the majors amongst gamers with at the very least 400 PA final yr and 100 this yr.

Precisely what’s happening with Acuña is unclear, however it might be health-related, as he had a scare early in spring coaching. Following a rundown throughout a February 29 recreation in opposition to the Twins, he felt soreness in his surgically repaired proper knee, which led to an examination by Dr. Neal ElAttrache, the orthopedic surgeon who repaired his torn ACL in 2021. Dr. ElAttrache discovered solely irritation within the meniscus of the knee, however that was nonetheless sufficient to sideline Acuña for 2 weeks as he rested earlier than resuming his preparation for the season.

We haven’t heard a lot concerning the knee since, so setting it apart for the second and merely specializing in his efficiency, two issues are manifestly obvious. First, he’s swinging and lacking far more typically than in 2023, and is especially struggling in opposition to four-seam fastballs. And second, he isn’t hitting the ball practically as exhausting, or in methods that may do as a lot injury.

As a result of Acuña had already come near a 40-homer, 40-steal season in 2019, ending with 41 homers and 37 steals, it was straightforward to give attention to his mixture of the 2 counting stats and marvel simply how excessive he might go within the latter class given the bigger bases and limitations on pickoff throws launched in 2023. Much less apparent was his dramatic discount in strikeout charge. He went from hanging out 23.6% of the time in 2022 — matching a profession low set the yr earlier than, down from the 26.4% charge he struck out over his first three seasons — to 11.4%. Per MLB.com’s Mike Petriello, his 12.2-point drop was the second-largest in AL/NL historical past, behind solely the 12.4-point drop of light-hitting Orioles shortstop Mark Belanger, from 21.5% in 1968 to 9.1% in ’69.

Belanger’s enchancment was aided by the league-wide redefinition of the strike zone within the wake of the Yr of the Pitcher, however Acuña didn’t have that working in his favor. As a substitute, he simply didn’t miss as typically, reducing his swinging strike charge from 10.9% to 7.8% and bettering his zone contact charge from 83% in 2022 to 87.8% in ’23. To this point this yr, he’s given all of these positive factors again and extra. He’s making contact on simply 78.1% of pitches within the strike zone, his lowest mark since 2020, and his swinging strike charge is a career-high 13.4%. Each his 15.4-point leap in strikeout charge and his 5.9-point leap in swinging strike charge are the majors’ largest, and he’s already bought 12 multi-strikeout video games, up from 10 for all of final season. All of this has occurred regardless of comparatively little change in Acuña’s chase charge; per Sports activities Data Options, he went from 28.5% in 2022 to 26.8% in ’23 and is again as much as 28.9% this yr.

Right here’s a take a look at Acuña’s whiff charge by Gameday Zone, based mostly on information via Might 6. Control that higher row:

As you may see from these charts, Acuña was susceptible to pitches within the higher third of the strike zone and better; he shored up that weak point in 2023, however has regressed. Right here’s a fuller take a look at his outcomes on pitches in that space, with 2021 information thrown in as properly:

Acuña punished these excessive pitches final yr, however he’s getting completely dominated by them this yr, along with his whiff charge practically doubling and his high quality of contact simply horrible. Pitchers seem to have caught on, as a result of they’re placing a better share of them in that neighborhood. They’re largely fastballs; final yr, 53.6% had been four-seamers and one other 20% sinkers, whereas this yr, the odds are as much as 66.4% for the four-seamers and 15.1% for the sinkers.

Much less dramatically, Acuña has fallen off in opposition to pitches on the outer third of the plate and additional exterior, although the impact is extra refined. Together with solely those which are within the strike zone (Gameday zones 3, 6, and 9 for these of you scoring at house), he’s gone from hitting .318 and slugging .588 in 2023 to hitting .409 and slugging .682 this yr, however his whiff charge has climbed from 22.3% to 36.1% on these pitches. If we embody those which are exterior the strike zone (Gameday zones 12 and 14), it’s a unique story, in that he’s gone from .292 AVG/.505 SLG with a 29.1% whiff charge to a .220 AVG/.340 SLG with a 43.4% whiff charge. He’s chasing all forms of pitches exterior the zone, and having a lot much less success at bad-ball hitting typically. Together with these which are contained in the interior third of the zone, he’s slipped from a .252 AVG/.405 SLG (.441 wOBA) with a 31.8% whiff charge to a .111 AVG/.156 SLG (.297 wOBA) with a forty five.9% whiff charge. Cripes.

Pitch-wise, as that growing share of excessive fastballs suggests, Acuña’s fall-off has been notably acute relating to four-seamers, no matter location:

I don’t learn about you, however I needed to decide my jaw up off the ground trying on the general 2023 versus ’24 splits, in addition to the location-based ones. Even on four-seamers within the strike zone, Acuña’s whiff charge has greater than doubled relative to final season, his wOBA on such pitches has fallen by greater than 50 factors, and his barrel charge has been greater than reduce in half. Exterior the zone, he hasn’t collected a single hit on a four-seamer this yr, after feasting upon them final yr.

Which brings us to Acuña’s high quality of contact, which has gone from prime shelf to merely fairly good:

Final yr, Acuña was within the 93rd percentile in barrel charge, the 98th percentile in hard-hit charge, and the one hundredth percentile in common exit velocity and the anticipated stats. This yr, he’s properly above common in most of these classes, however it’s nonetheless a really totally different image:

Woof. The lack of energy is especially notable, and you may see from the bars additional down how badly he fares relating to whiffs and strikeouts. The one class the place his percentile rating has improved is in stroll charge.

I didn’t present it above, however it’s value noting that Acuña’s not hitting it within the air as typically as final yr. His groundball charge has elevated from 49.5% (which was a profession excessive) to 51.6%, along with his fly ball charge dropping from 30.4% (which was a profession low) to 24.2%. His groundball-to-fly ball ratio has elevated from 1.63 to 2.14, even whereas his common launch angle has elevated barely from 7.4 levels to eight.5. His candy spot charge — the proportion of batted balls hit with launch angles starting from eight to 32 levels — has dropped solely barely, from 33.6% to 31.9%, however it has dropped nonetheless.

If I hadn’t pulled up Acuña’s numbers and charts myself, I’d have a tough time believing that the 2023 and ’24 ones are from the identical participant. As to the why, I don’t know whether or not his issues are mechanical, health-related, psychological, or a mixture of all three, and as all the time, I’m reluctant to take a position. Nonetheless, it’s hanging the best way Acuña’s 2023 numbers resemble his blazing pre-injury half-season in ’21, whereas his comparatively mediocre ’24 numbers bear nearer resemblance to his tentative return in ’22, which places me in thoughts of this quote from late in that season:

Ronald Acuña Jr.: “It’s all a part of the method & I’m hoping for higher days. However I’ve to say, for instance, the knee with my swings, it doesn’t all the time really feel the identical. Some days I’ve confidence in it, some days I don’t really feel like I’ve confidence in it, and it’s not the identical.”

— David O’Brien (@DOBrienATL) August 5, 2022

We haven’t heard a lot about Acuña’s knee since he was sidelined, although O’Brien did be aware that after he tried a sliding catch in an April 16 recreation, he walked gingerly and pointed to his proper knee when the staff’s coach attended to him, although he stayed within the recreation. If the joint is bothering him, that also doesn’t clarify why his dash pace percentile rating is in keeping with final yr (67th percentile then, 69th now) or why he’s stealing bases at an identical clip. After being thrown out by the Purple Sox’s Reese McGuire on Tuesday, he’s 14-for-16, placing him on tempo for 69 steals, along with his success charge bettering from 84% to 88%.

Final week, Acuña did string collectively three multi-hit video games for the primary time all season, going a mixed 7-for-14 with a double and a homer in a single recreation in opposition to the Mariners and two in opposition to the Dodgers. However even if you happen to zoom out to squint at some arbitrary endpoints — he’s hitting .381/.409/.571 via the primary week of Might! — a five-game pattern is hardly massive sufficient to be convincing.

Acuña isn’t the one one of many Braves’ prime hitters who has opened the season in a funk. Matt Olson has dropped from 160 to 91 when it comes to wRC+, Austin Riley from 127 to 104, and Michael Harris II from 115 to 96. Nonetheless, none of these falloffs are as dramatic as Acuña’s, or are taking place to a participant who’s on the brief listing of the sport’s greatest. Absent a transparent clarification, I’d guess that his proper knee is a significant component in what’s happening, however till Acuña presents us extra perception, we’ll simply should marvel what’s occurred to the 2023 NL MVP.